1. Technical Field
This invention relates to inorganic resins in composition of aqueous solution of inorganic metal phosphate, oxy-boron compound and wollastonite compound; to various additives for said composition; to processes for forming said resin and the resin product; to products manufactured by said resin composition and said process. The unique feather of this invention is that pot life of the fresh resin and temperature increase of the resin during setting reaction can be controlled so that its pot life can be between few minutes to an order of magnitude of several hours or longer; whereas hardened resin and resin product have good material properties and wide range of use. Both cellular and non cellular structures can be obtained.
The resin of the present invention can be used as adhesives and binders. In terms or properties, inorganic resin of the present invention and its products lies between those such as e.g. Portland cement and those such as e.g. technical ceramics. Fresh mixture or the resin has low viscosity, is storable at low temperatures and easy to use; while the hardened resin is strong, durable, resistant against mild acid attack, fire-proof, and stable at high temperatures. It is suitable to make, such as but not limited, adhesives, binders, coatings and inorganic composites reinforced by fillers and fibres including all glass fibres, used both at low and high temperatures.
2. Description of the Related Art
Wollastonite has been employed not long time ago as primary material in phosphate cement compositions. Only few formulations are known in that field so far, they all have quick setting characteristics. Hardening of these compositions usually occurs at ambient condition in a range from several minutes to ca 10-20 minutes after forming of the cement, which is practically-impossible to be used in applications such as that of composite materials. Large amount of heat production is another typical phenomenon of the traditional phosphate cements which may produce defects inside of the material and affects negatively on material properties. When wollastonite is employed as primary material in the composition, the quick setting may result in extra voids and cracks in structure of the material due to formation of CO.sub.2 during the setting process produced by decomposition of calcite (CaCO.sub.3) contained in the wollastonite, which further undermines strength and durability of the material. U.S. Pat. No. 3,804,651 dated Apr. 16, 1974 to C. E. Semler discloses a quick setting gel binder of phosphate solutions and wollastonite. The cured binder shows a good mechanical strength and durability, but its fresh mixture gels quickly and is claimed as a quick setting composition. U.S. Pat. No. 4,375,516 dated Mar. 1, 1983 to Jeffery L., Barrall et.al discloses a material in composition of aluminium phosphate solution and solid component containing wollastonite. This composition usually sets in several minutes in the temperature range of 4-25.degree. C. U.S. Pat. No. 4,792,359 dated Dec. 20, 1988 to Jeffery L., Barrall et.al discloses a method to prepare composite materials by hot pressing the mixture of phosphate cement and varies fibres at about 85.degree. C. under pressures, which takes advantage of the quick setting.
As a summary, these inorganic phosphate compositions are found not related to this invention. In terms of composition, no oxy-boron compound is used to extend pot life of these phosphate cement compositions; in terms of setting time, all available compositions has a quick setting; in terms of pot life during which period the mixture keeps flowable, no information is available probably due to the quick setting; in terms of application, all available compositions is used for purposes which needs quick setting.
The inorganic resins of the present invention have a controllable pot life and temperature increase in its fresh state; and have good material properties for the hardened resin, such as, e.g., good mechanical strength, durability, resistance against mild acid attack, high scratch hardness, non flammability, high temperature resistance, and good adhesion with other materials such as fibres including glass fibres,